The most effective way to test an LED for performance is to use a special device - a multimeter, which is often called a tester. The device is a measuring device that can perform several functions. You can select them using the knob located on the front panel.
Content
- Continuity testing
- Check without desoldering
- The performance of light emitting diodes in flashlights
- Tips & Tricks
Continuity testing
Every multimeter, no matter how expensive it is or which company it was produced by, necessarily has a function for checking the LED performance. This is the so-called dial tone.
Before ringing the LED with a multimeter, it is necessary to set the tester mode switching knob to the dialing mode. Then attach the black and red test leads of the multimeter to the contacts of the tested device. Thanks to this test method, it is also possible to determine how much power the LED has.
When connecting the tester, the polarity of the tested object must be taken into account. Its anode should be connected to the red probe, and the cathode to the black one. If you connect the probes incorrectly, the device will not show anything. When connected correctly, the LED should start emitting light.
When checking the diode for operability, it is important to take into account the following feature: the tester's electric current, set to dial mode is rather weak, so it may not have any effect on light bulb. The object being checked may be perfectly functionalm, but will not glow due to insufficient current strength.
There may be another consequence of the weak current: the LED will start to glow, but its radiation will be so scanty that it will not be possible to see it in normal daylight. Before proceeding with the test, it is recommended to reduce the brightness of the external light. If for some reason this cannot be done, you should pay attention not to the device itself, but to the measuring device, more precisely, to its readings. If it is serviceable, then the figure shown by the tester should be different from one.
You can even ring a very powerful diode with a multimeter. However, the disadvantage of this method is that it will not work to check the elements that are soldered into the microcircuit. To check the LED in the microcircuit, you need to use special adapters that are connected to the tester probes.
Check without desoldering
To check with a multimeter without soldering the LED from the microcircuit, you can use small metal tips, the role of which can play, for example, ordinary paper clips. For reliable insulation of the wires to which the lugs are connected, a textolite gasket should be used. In this case, the entire structure must be wrapped with electrical tape.
After completing all these simple steps, you will get a reliable adapter., by means of which it is easy to achieve contact of the tester probes with the cathode and anode of the LED being tested for performance.
Also, without soldering from the microcircuit, you can check the diode for serviceability.. For this it is enough:
- Set the measuring device to dial mode.
- Connect the probes with an adapter to the contacts of the tested object.
- Check if the light is on or not.
As in the case of a regular dialing, which is carried out without an adapter, you may have to turn off the external lighting or weaken it in order to notice the dim glow of the device light.
The performance of light emitting diodes in flashlights
It is possible to check the efficiency of the LED located in a small flashlight without much difficulty.
This check is carried out in several stages.:
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It is necessary to disassemble the flashlight and get the microcircuit out of it, into which the LED is soldered. - Metal tips that were previously soldered to the tester probes should be connected to the device contacts. In this case, it is important to observe the polarity, not to confuse the black probe with the red one.
- The multimeter switches to dial mode.
Immediately after that, it will become clear whether the item being checked is serviceable. If he lights up, then everything is fine with him. If there is no radiation, then the LED is in a faulty state.
Tips & Tricks
To test an LED with a tester, it is important to be able to distinguish between a cathode and an anode. In fact, the difference is easily visible visually: the cathode is usually noticeably shorter than the anode. You can remember this: the word "cathode" begins with the letter "k", therefore, this contact is short. However, even if you connect a multimeter without observing the polarity, nothing bad will happen. The LED element will simply not receive current and therefore will not light up.
Instead of guessing each time you check which contact is “positive” and which is “negative,” it’s better to remember once forever. This will save time. It is not uncommon to measure the resistance to check if the LED is working. However, this method of verification is not very widespread, because before using it, it is necessary to determine the technical parameters of the device.
As seen, checking the performance of an LED using a tester is a fairly simple procedure. This will not take long. You will not have to make any physical efforts either. And the financial costs for such a check are practically negligible, since the used device is sold at a very low price.
